'The middle is getting squeezed," former Republican Rep. Tom Davis told The Hill newspaper. But his comment vastly understates the crisis in the capital. Activists in both parties have declared war on moderates. The ideological gap between the two parties is widening rapidly. Paralysis is pervasive.

Political scientist Keith Poole of the University of Georgia, who studies voting patterns, told the National Journal: "We are clearly as conflicted as we've been since 1905. The parties are, I think, completely dysfunctional and incapable of acting on major policy."

The National Journal reports that as recently as 1999, more than half of all House members could be called centrists, with voting records somewhere between the most liberal Republican and the most conservative Democrat. That number has now dropped to almost zero, and next year the president -- whoever he is -- will face an even more polarized Congress.

We have become Europe, with ideologically based parties, rigidly enforced discipline and fast-fading bipartisanship. That system might work in smaller, more homogenous countries, but it's a disaster in a nation this large and diverse. Washington is not just "completely dysfunctional" today, it's downright un-American.

Our political tradition has always placed pragmatism over purity, reality over rigidity. Americans dealt with the world as it was, not as we wanted it to be. We didn't spout dogma; we solved problems. Compromise was once a virtue, but today it's a sin. The center is not getting "squeezed," it's getting choked to death, and both parties are to blame.

Start with the Democrats. In Pennsylvania last week, two moderate congressmen -- Jason Altmire and Tim Holden -- lost to primary challengers from the left. Both belonged to the centrist group known as Blue Dogs, which included 54 House Democrats after the 2008 election. Today their ranks have dwindled to about 25, and in the next Congress that number will drop below 20.

One reason Altmire and Holden lost was redistricting. Republicans who control the Pennsylvania legislature packed as many Democrats as possible into a few districts, and both lawmakers faced more left-leaning electorates than they had in the past. But they were also opposed by outside groups -- from MoveOn to the League of Conservation Voters -- who punished them for straying from liberal orthodoxy. (Both lawmakers voted against Obama's health-care bill, for example.)

The leftist website Daily Kos crowed about the outcome, boasting that the demise of the Blue Dogs would create "a more effective and progressive Democratic party." Wrong.

This is not a left-leaning country. In the last election, only 22 percent of all voters called themselves liberals (32 percent picked a conservative label and 44 percent moderate). The loss of Blue Dogs like Altmire and Holden might make the Democrats a more "progressive" party, but also a far smaller and less "effective" one. Anyone who argues otherwise simply cannot count.

Republicans engage in the same kind of fantasy politics from the right. In Utah, hard-core ideologues have challenged the renomination of Sen. Orrin Hatch, a loyal conservative but a professional legislator who once prided himself on working with Democrats like the late Ted Kennedy. No more. Hatch has turned sharply to the right and renounced his heresy, and as a result he will probably survive a primary fight in June. But he doesn't dare work with Democrats anymore.

In Indiana, another Republican conservative who doesn't believe Democrats consort with the devil, Sen. Richard Lugar, is facing a fierce primary challenge next week from state Treasurer Richard Mourdock. Keepers of the right-wing flame, from the National Review to Sarah Palin, have weighed in against Lugar because he fails their purity test. Even if he wins, he will, like Hatch, be less likely to work with his old Democratic friends in the future.

On the presidential level, too, centrist impulses are sputtering. Not that long ago, Democrat Bill Clinton ran for re-election declaring that "the era of big government is over." His successor, George W. Bush, campaigned as a "compassionate conservative" who would unite, not divide, the nation.

Now, Mitt Romney is desperately calling himself a "severe conservative" and running as fast as he can from the label that he once proudly embraced, "Massachusetts moderate." President Obama famously told the Democratic National Convention in 2004, "There is not a liberal America and a conservative America -- there is the United States of America." When was the last time you heard him talk like that?

The war on moderates is escalating. The extremes are winning. And the American system is losing.